Acoustic diaphragm



N. BALDWIN ACOUSTIC DIAPHRAGM Filed Oct. 1, 192? 9 w/w/ Inventor PATENT OFFICE.

NATHANIEL BALDWIN, OI EAST MILL CREEK, UTAH.

ACOUSTIC DIAPHRAGE.

Application filed October 1, 1987.. Serial No. 228,888.

The present invention appertains to acoustic diaphragms and particularly to those used in loud speakers having no horns.

The object is to obtain increased efficiency and purity of reproduction by providing a diaphragm which is extremely light yet rigid and responsive.

I attain this object by the mechanism illustrated in the accompanying drawing in which Fig. 1 is a rear elevation showing the diaphragm and its housing and Fig. 2 is a section of the same device along the line AB of Fig. 1.

As shown in the two figures of the drawing the diaphragm 1 consists of a sheet of paper or other membraneous material, having four depressions 2, to stiffen it and two cross beams 3 of light material such as Wood cemented to the paper at the edges of the depressions. These cross-beams are matched and sealed together at the center with glue or otherwise, and a connecting rod 4 setinto the jointed portion communicates the movement of the operating element (not shown) to the diaphragm.

The housing 5 consists of a rectangular frame, to one ed e of which the flexible outer edge of the diap ragm 1 issecured.

It will be seen that with this form of diaphragm, having several depressions which in consequence of the number may be comparatively small, and with beams partly S11I rounding them, very light material can be used and yet sufficient rigidity obtained.

A specific form of diaphragm is herein described, but it is apparent that the invention disclosed can be applied to a variety of forms 4 and for various purposes.

The diaphragm may be round, oval, or oblong and there may be any desired number of reinforcing beams. The diaphragm may be used in connection with a coactmg element, or operating means, to reproduce sound, as in aloud speaker or phonograph reproducer, or it may be used in connection with other forms of coacting elements to amplify or record sound, as in a microphone, or phonograph recorder.

I claim:

1. An acoustic diaphragm comprising a light stiff beam, a light thin sheet sealed to said beam and stiffened by non-plane deformation, and means operatively to connect said beam with a coacting element.

2. An acoustic dia hra m comprisin a light stiff beam, 8. lig t thin sheet scale to said beam and stiffened by curvature on either side of said beam, and means operatively to connect said beam with a coacting element.

3. An acoustic diaphragm comprising a light stiff beam, a light thin sheet sealed to said beam and stiffened by depressions formed in said sheet on either side of said beam, and means operatively to connect said beam with a coacting element.

4-. An acoustic diaphragm comprising a plurality of cooperating light stiff beams, a light thin sheet sealed to said beams and stiffened by non-plane deformation, and means to connect said beams with operating means.

5. An acoustic diaphragm comprising a plurality of light stiff beams rigidly connected together, a light thin sheet sealed to said beams and stiffened by depressions formed in said sheet, and means operatively to connect said beams with a, coacting element.

6. An acoustic diaphragm comprising a plurality of intersecting light stiff beams, a light thin sheet sealed to said beams and stiffened by depressions formed in said sheet, and means operatively to connect said beams with a. coacting element.

7. An acoustic diaphragm comprising a plurality of light stiff beams radiating from a junction, alight thin sheet sealed to said beams and stiffened by depressions formed in said sheet between said radiating beams, and means operatively to connect said beams with a meeting element.

8. An acoustic diaphragm comprising two light stiff intersecting beams, a light thin sheet sealed to said beams and stiffened by depressions formed in said sheet on either side of said beams, and means operatively to connect said beams with a coacting element 9. An acoustic diaphragm comprising a plurality of light stiff beams rigidly connected together, a light thin sheet sealed to said beams and stiffened by depressions formed in said sheet, and means to connect said beams with operating means.

10. An acoustic diaphragm comprising a pluralit of Eight stifl beams radiating from a junction, a li ht thin sheet sealed to said beams and sti ened by depressions with curved bottoms formed in said sheet between said radiating beams, and means operatively to connect said beams with a coasting element.

NATHANIEL BALDWIN. 

